Currently available surface deicing compositions use rock salt and other such corrosive materials. Glycol-based formulations, urea-containing formulations, and methanol-containing formulations have been proposed and used for airplane runways. However, these formulations are toxic, corrosive to metals, and often flammable.
U.S. Pat. No. 5,064,551 to Smith teaches acetate and formate solutions for use as deicers which include metal corrosion inhibitors in the form of phosphates and nitrates and include EDTA as a surfactant. It is felt that such compositions not only fail to provide adequate overall metal protection, but the inclusion of nitrates is considered potentially damaging to the environment. Calcium magnesium acetate (CMA) granular materials, such as those disclosed in U.S. Pat. No. 4,913,831, are environmentally acceptable compositions for deicing but do not act instantly.
There remains a need for effective, environmentally acceptable deicing solutions for use on road surfaces, particularly airplane runway surfaces, which are nontoxic, nonflammable, and essentially noncorrosive to metals. Because deicing formulations dispersed on runways are often ultimately washed into a storm drain system or a waterway, it is important that the solution be nontoxic to the environment, particularly aquatic life. It is also important that such deicing formulations be able to function well in a variety of weather conditions, both as a deicer to remove accumulated ice and snow, and as an anti-icer, to prevent ice formation on a runway- It is further important that such deicing formulations are not slippery, when applied to a runway surface or the like, otherwise they could undesirably reduce the traction of the surface for aircraft and other vehicles. It is an object of the present invention to provide effective surface deicers, particularly suitable for airport runways, which can be easily applied, act quickly, are nonslippery, and are effective over a wide range of temperatures and weather conditions.